6451619387781 has 16 divisors (see below), whose sum is σ = 8687492941248. Its totient is φ = 4258414320000.

The previous prime is 6451619387777. The next prime is 6451619387839. The reversal of 6451619387781 is 1877839161546.

It is not a de Polignac number, because 6451619387781 - 2² = 6451619387777 is a prime.

It is a super-2 number, since 2×6451619387781² (a number of 26 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6451619337781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18874465 + ... + 19213241.

It is an arithmetic number, because the mean of its divisors is an integer number (542968308828).

Almost surely, 2^{6451619387781} is an apocalyptic number.

It is an amenable number.

6451619387781 is a deficient number, since it is larger than the sum of its proper divisors (2235873553467).

6451619387781 is a wasteful number, since it uses less digits than its factorization.

6451619387781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 401732.

The product of its digits is 60963840, while the sum is 66.

The spelling of 6451619387781 in words is "six trillion, four hundred fifty-one billion, six hundred nineteen million, three hundred eighty-seven thousand, seven hundred eighty-one".